I have a different approach to parties. I would cook the brisket my usual way (low and slow) the weekend before the party. After it is ready (probe tender, rested) I put it in the refrigerator to chill down.
Once cool, not cold, I pull it out, slice it, and then vacuum seal it with my seal-a-meal. I do about 1.5# per bag. I take the drippings and seal a bunch of it as well.
On party day, I pull the meat out of the frig/freezer, have one or two large stock pots of boiling water going, and drop the bags into the water for about 30 minutes. At the end of that time, I pull them out, slice them open, and put the piping hot beef on the platter for serving. I drizzle them with some of the heated drippings, and it tastes like it is fresh from the smoker.
This eliminates stress on party day, gives time to correct things that might go wrong, and I am not a zombie at the party for having gotten up at 4 a.m. to start cooking!
Regards, Riz58 Char Broil Akorn, Bandera, and Masterbuilt Electric Smoker